Taken from RCT4's facebook:
"We hear everyone's comments on the new RollerCoaster Tycoon game and want to let you all know that the mobile game and PC experience will be 2 completely different games. Both games will release this year. The mobile game will include social features (sharing with friends, leaderboards) and the PC experience will have even more features and functionality. We are excited to bring these games to you soon!"
First, they say they are completely different games, BUT then they say the PC version will have more features and functionality... that's like saying it will be the same game, just with more stuff... So don't expect the PC version to be very different from the mobile one